1. Field of the Invention
This invention in general relates to photography and in particular to camera apparatus having a built-in, close-up lens arrangement.
2. Description of the Prior Art
Photographic cameras of the type having exposure control systems that automatically operate to provide the correct amount of exposure delivered to a film under both natural and artificially created lighting conditions are well-known in the prior art. Under natural lighting conditions such cameras generally operate to provide proper exposure control over a predetermined range of scene brightnesses and under artificially created lighting conditions, such as those created by a built-in strobe or the like, operate to provide proper exposure over a predetermined range of subject distances related to the focus range of the camera objective taking lens system.
In cameras having fixed focus objective taking lens systems, the nearest distance at which properly exposed and sharply focused pictures can be obtained is determined by the near focus of the objective lens system even though proper exposure can generally be provided by the camera exposure control system for subjects located closer to the camera than the near focus of the camera objective taking lens system.
It is therefore a primary object of the present invention to provide a built-in, close-up lens arrangement for use with a camera having an automatic exposure control system to extend the near subject distances at which correctly exposed, properly focused pictures can be obtained.
It is another object of the present invention to provide a built-in, close-up lens arrangement for use with a camera of the type having an automatic exposure control system and a built-in foldable type electronic strobe such as that shown and described in considerable detail in U.S. Pat. No. 4,231,645 issued on Nov. 4, 1980 to Carl W. Davis et al. and entitled "Camera with Telescoping Dual Actuators". In this patent, a folding electronic strobe unit is mounted on a camera housing for movement between an erect operative position and a folded storage location.
The built-in, close-up lens arrangement of the present invention as described hereafter is particularly suitable for use with the type of camera structure disclosed in the Davis et al. patent and operates, inter alia, to automatically return a close-up lens to a storage location in response to folding the type of electronic strobe of Davis et al. into its storage location.
An example of a prior art camera having an optical lens system for automatically changing the focal distance of the objective lens in response to movement of an artificial lighting device between an operative and an inoperative position is shown and described in U.S. Pat. No. 3,598,031 issued to Donald M. Harvey on August 10, 1971 and entitled "Photographic Camera With Means For Varying A Focus Adjustment To Photograph An Artificially Illuminated Subject". Harvey, however, apparently provides no option for changing the focus of the lens and would not be suitable for use with a camera of the Davis et al. type. It is therefore another object of the present invention to provide a built-in, close-up lens arrangement of the type that can be optionally used to change the near focus of a camera having a built-in foldable artificial lighting device.
Other objects of the invention will in part be obvious and will in part appear hereinafter. The invention accordingly comprises the apparatus possessing the construction, combination of elements, and arrangement of parts which are exemplified in the following detailed disclosure.